I don't know how to find the rest of the solutions...
Please don't just give me an answer, tell me what you did to get from the factors found from rational roots to the solutions of the equation.

Thanks

assuming what you have so far is correct, just divide (via long division or synthetic division) the polynomial by each of the factors you found (divide it by one, then divide the answer by the next, then that answer by the last). this will result in a quadratic that you can factor over the reals (if there are real solution(s)) to get the remaining two factors.